+OK 9378 octets Received: from smtp00.nwnexus.com (smtp00.nwnexus.com [192.135.191.25]) by mail3.halcyon.com (8.8.8/8.8.8) with ESMTP id LAA12543 for ; Fri, 23 Apr 1999 11:53:17 -0700 (PDT) Received: from mc.egroups.com (mc.egroups.com [207.138.41.138]) by smtp00.nwnexus.com (8.8.8/8.8.8) with SMTP id LAA24002 for ; Fri, 23 Apr 1999 11:50:37 -0700 (PDT) Received: from [127.0.0.1] by mc.egroups.com with NNFMP; 23 Apr 1999 18:50:33 -0000 Mailing-List: contact h-bd-owner@egroups.com X-Mailing-List: h-bd@egroups.com X-URL: http://www.egroups.com/list/h-bd/ Delivered-To: listsaver-egroups-h-bd@egroups.com Received: (qmail 13376 invoked by uid 7770); 23 Apr 1999 18:50:28 -0000 Received: from mail12.svr.pol.co.uk (195.92.193.215) by vault.egroups.com with SMTP; 23 Apr 1999 18:50:28 -0000 Received: from modem-30.flunitrazepam.dialup.pol.co.uk ([62.136.68.30] helo=oemcomputer) by mail12.svr.pol.co.uk with smtp (Exim 2.12 #1) id 10akC9-0000W6-00; Fri, 23 Apr 1999 18:56:57 +0100 Message-ID: <005101be8dba$77620aa0$02000003@oemcomputer> Reply-To: "Ian Pitchford" From: "Ian Pitchford" To: , Date: Fri, 23 Apr 1999 19:50:50 +0100 Organization: http://www.human-nature.com/ MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.00.2014.211 X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2014.211 Subject: [h-bd] Children of Prometheus: The Accelerating Pace of Human Evolution Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8bit Status: 15 April 1999 Nature 398, 575 - 576 (1999) © Macmillan Publishers Ltd. Prometheus unwound ADRIENNE ZIHLMAN Children of Prometheus: The Accelerating Pace of Human Evolution by Christopher Wills Perseus: 1998. 310 pp. $25 Books about human evolution tend to fall into two categories: they either emphasize how much like the apes we are in terms of our murderous, hierarchical or sexual behaviour, or they elaborate the contrast between hairy, jungle-bound quadrupeds and our brainy upright selves. Christopher Wills, a molecular researcher, takes the second tack. In his view, we children of Prometheus have stolen fire, language and high technology from the gods of things-as-they-are and have evolved, and we continue to evolve so rapidly that we have left our relatives, the chimpanzees, gorillas and orang-utans, in the Darwinian dust. Although Wills acknowledges that human and chimpanzee DNA are 98% identical, he is even more impressed by the degree to which "our big-brained, clever-handed, highly social, language-speaking selves" have outpaced our hirsute relatives in the hominoid Olympiad. In support of his thesis that the rate of human evolutionary change is accelerating, Wills recounts a number of case studies: how the Tibetans have acquired physiological adaptations to high altitudes; how human haemoglobin variants confer resistance to malaria; and even how one's position in the hierarchy of the British Civil Service affects longevity. He profiles the changing character of Europe, with declining birth rates and rising immigration that will mix gene pools and lead to increased diversity. Turning from the human present to its past, Wills reviews the latest versions of the human fossil record and concludes that the story of the extinct and presumably less successful Neanderthals represents "the road not taken" by our own species. This judgement may be a trifle premature, as the Neanderthals inhabited Europe and the Middle East for several hundred thousand years and Homo sapiens has been around for no more than 200,000 to date. The extensive morphological differences between Neanderthals and modern humans is barely mentioned, but the DNA comparison reported last year is recounted in entertaining detail. Examining the earlier fossil record with an eye to 'molecular-clock' timing of the human-chimpanzee divergence to about five million years ago, Wills 'predicts', as others have done, that the earliest hominids will be chimp-like, and in fact australopithecines very much resemble bipedal chimpanzees. Wills unquestioningly accepts Tim White's claim that his 4.4-million-year-old Ardipithecus ramidus is the earliest-known hominid, although the lack of published evidence for the fossil's bipedality has aroused considerable scepticism in the palaeoanthropological community. Wills does not mention Meave Leakey's more recent discovery in Kenya of Australopithecus anamensis, an undisputed hominid possessing limb bones that demonstrate bipedality four million years ago. This book, though often interesting and informative, seems to suffer from imprecision in the use of the word 'evolution' and from a lack of coherent focus. It is not always clear whether Wills is referring to genetic, morphological or cultural evolution, as he switches vertiginously from one to another. Sometimes his argument rests entirely at the molecular-genetic level (changes in gene frequencies in populations), and the morphological level is omitted, as in the Neanderthal account. At other times, he abandons quantitative molecular data and builds a hominoid family tree from a motley array of physical and behavioural features, "including the ability to speak, the ability to recognize oneself in a mirror, the ability to walk bipedally, the degree of difference in size between the two halves of the brain, the amount of thumb mobility, the period over which the young are nursed, the amount of skeletal muscle strength, the presence of breast in a nonlactating female, and a number of others". Wills concedes that chimpanzees are stronger than humans, but deduces from his anthropocentric items that human evolution has occurred at about 10 times the rate of ape and monkey evolution. How easy it would be to argue the contrary from the chimpanzee point of view: that we are a most retrograde species who have lost our body hair, facility in climbing trees, female sexual swellings and numerous other primate assets. A more neutral description would merely state that we are adapted to a way of life very different from the ancestral one, and that small changes at the molecular-genetic level can obviously result in major phenotypic and behavioural modifications. The mystery of the big human brain and what goes on inside it intrigues Wills, as it has fascinated so many others. The last few chapters, some of the best in this book, deal with the genetic aspects of diseases such as narcolepsy, attention-deficit hyperactivity disorder, schizophrenia, Alzheimer's disease and the much-debated factors in IQ. He speculates that rapid generational changes in microsatellite DNA -- which are known to account for several neurological diseases, such as Huntington's chorea -- could be a mechanism for intellectual improvement. In Wills's opinion, our grandchildren will surely be smarter than us, and within a few generations Einsteins and Mozarts will be commonplace. These optimistic exegeses, while not without interest, illuminate by omission how little we understand about the molecular, functional and adaptive factors that have inflated the human cranium and its contents threefold over the past five million years. In his last chapter, "Our evolutionary future", Wills unhesitatingly predicts an even bigger-brained advent that will carry us beyond the Solar System to planets of other stars. I admire the courage of someone who can make such projections for a society that cannot predict the next election result or the weather next week. Are we still evolving? This is the question Wills asks at the beginning and end of his volume, and at many points in between. The answer is, of course, that we are: as are chimpanzees, gorillas, orang-utans, crocodiles and bacteria. Are we really evolving much faster than those other organisms? Not at the molecular level, according to present evidence. Even bacteria, the oldest and most 'primitive' forms of life, show a degree of flexibility in their ability to survive and become resistant to our most potent antibiotics that our own species has yet to prove it can match. In Darwin's concept of evolution, the direction of evolutionary change is unpredictable, dependent as it is on changing conditions and the vagaries of natural selection. Wills's confidence as to which evolutionary features are good or bad, superior or inferior, faster or slower, conveys perhaps a hint of Promethean hubris. For the future of the species, let's hope that our grandchildren will, as Wills predicts, be smarter than we are. Adrienne Zihlman is in the Department of Anthropology, University of California, Santa Cruz, California 95064, USA. ------------------------------------------------------------------------ V-Tech Computer For Kids! Challenge your kids with activities in math, trivia, vocabulary, spelling, grammer! Looks just like your PC! 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